Fan



G. F. BAHR Aug. l1, 1942.

FAN

Filed April 5. 1940 Patented ug. 11, 1942 UNITE STATES PATENT OFFICE FAN Application April 5, 1940, Serial No. 327,936

13 Claims.

This invention relates to fans, and, more particularly, to fans for circulating air.

The present invention is particularly adapted for fan constructions, wherein the blades thereof are formed of rubber or other flexible material, but, in the broader aspects of the invention, it is not limited to a flexible blade construction.

As previously proposed, rubber or exible blades have been mounted to the cap or hub generally by forming an edge of the blade with a locking ridge or shoulder which could be slipped through an enlarged portion of a closed end slot substantially the width of the thickness of the blade or by forming the hub in two sections with meeting edges forming, when assembled together, a plurality of slots for clamping opposite faces of a blade member.

In assembling these constructions, many manipulations have been required, and it is an object of this invention to provide a fan construction which can be assembled with relatively few operations.

According to the present invention, the hub is formed as a single piece having formed therein a plurality of slots opening at the rear edge of the hub. The blades are assembled by merely sliding the same into the opened ends of the slots until they are properly positioned on the hub. This obviates the threading of the enlarged portion of the blade through the enlarged portion of a slot such as has been previously proposed. The hub furthermore being of one piece presents a more pleasing appearance than the two part hubs, as no line of jointure between the parts mars the appearance of the hub of the present invention.

The blades are held against radial movement of the hub by providing a plurality of projections or the like on that part of the blade received within the hub to engage the inner surface of the hub and hold the blade properly mounted in the slot.

The hub, as the blade-receiving slots open at the rear edge thereof, is somewhat flexible and accordingly the hub is reinforced at the rear edge by means also formed to hold the blades against sliding movement in the slots. This means preferably comprises a plate or disk having formed therein a circular groove having a hold the same against sliding movement in the slots.

The hub is mounted to the shaft of a motor by means positioned in the hub so as to extend longitudinally of the hub along its axis of rotation. In securing the hub to the shaft, in this manner, unbalance of the hub is avoided and the necessity of counterbalancing is removed for the hub is dynamically balanced. The means for securing the hub to the shaft comprises a clamping element sleeving the shaft and cooperating with the reinforcing disk to clamp the hub to the shaft as well as to clamp the reinforcing disk tightly against the rear of the hub to reinforce the same.

Other features and advantages will hereinafter appear.

In the accompanying drawing:

Figure 1 shows a front View of the hub and blade assembly.

Fig. 2 shows a side View of the same assembly.

Fig. 3 is a side view of the hub with the blades removed.

Fig. 4 is a sectional view of the hub showing one blade mounted in its slot and with the hub secured to the shaft of a motor of which only a fragmentary part is shown.

Fig. 5 is a view similar to Fig. 4, but showing a modified form of the invention.

As shown in the drawing, the fan of the present invention comprises a hub I0 having a plurality of blades Il projecting therefrom and secured thereto to form a unit which is adapted to be mounted on the shaft of a motor or other driving means.

In the illustrated form of the invention, the hub l0 isprovided with a plurality of slots l2 extending from the rear edge I3 forwardly of the hub. The slots preferably are formed so that they will impart to the blades, when the blades are mounted therein, a proper curvature for eicient displacements of air. To this end, the slots are helically shaped and extend forwardly and about the peripheral surface of the hub.

In the preferred form of the invention the blades are formed of exible rubber or material having similar properties.

Three such blades are used, and, according to the present invention, have their centers spaced about the hub at apart. The blades extend around the hub for approximately and have their adjacent edges in spaced overlapping relation. By using three blades and positioning them in the manner shown in the drawing, agreater The blades may be secured in the slots in any convenient manner. In the preferred form of the invention, the edge positioned `within .the hub is provided with a plurality of lugs IE'projecting from opposite sides of the blade. The lugs I5 engage the inner surface of the hub adjacent the slots and prevent the blades from radial movement outwardly of the hub.

In `formingthe edge with such projecting lugs, a much greater flexibility is imparted `to the blades than if the series of lugs weremade into a solid rib. A solid rib may be used, however, when such flexibility is not required.

As shown inFig. 3, the-hub, as the slots I2 open at the rear edge thereof, is quite flexible, and, to impart the desired rigidity to the hub so as not Yto be drawn out of dynamic balance upon rotation, the present invention provides means for reinforcing the rear edge of the hub. For this` purpose, there is provided a disk I6 formed with Aan annular. groove Il having a diameter equal to the diameter of the rear edge of the hub.

The disk, asin the form of the invention shown in Fig. 4, is mounted to the hub with the rear edge I3 disposed in the groove I'I. It will be'seen that the disk I6, when .mounted to the rear edge of the hub will reinforce the rear edge of the same and impart the desired rigidity thereto.

The disk is provided with a Vflange I8 which engages the outer surface of the hub adjacent the rear edge I3 thereof and is of such size and shape. as to overlie and cover the enlargedportions I4 of the slots I2 vso that thev appearance ofthe hub is not marred by these enlarged portions. The forward. edgeof Vthe flange engages the trailing edge of the blades II and will hold the blade from sliding. in the slot when the fan is in operation.

To mount the fan and hub assembly to the shaft of a motor or other driving means, the disk I6 is provided with a sleeve 20 extending axially of the hub and concentric with the axis of rotation of the hub. The sleeve 2l] has a camming surface 2| formed in its bore. Mounted to slide in the bore of the sleeve 20 is a sleeve 22 having a bore of sufficient size to receive amotor shaft 23. The end of the sleeve 22 adapted to receive the motor shaft is split so as to form a plurality of clamping elements 24.

The clamping elements 24 are provided with camming surfaces 25 on their exterior adapted to engage and cooperate with the camming surface 2| formed in the bore of the sleeve 20. The other end of the sleeve 22 is provided with a threaded socket 26 adapted to receive a threaded bolt 21 mounted in a recess 23 at the nose of the hub so as to lie below the surface of the same.

The bolt extends along the axis of the hub, and, upon being threaded into the socket 26, draws the sleeve 22 outwardly toward the nose of the hub to cause the camming surfaces 2l in cooperation with the camming surfaces 25 t'o cam the clamping elements 24 to move into `clamping relation with the end of the motor shaft. The action of the camming surfaces also will cause the disk IE to be pulled inwardly of the hub and tightly against the rear edge I3 of the hub. The disk I6 is dished somewhat to accommodate the end of a motor casing 30.

As all the elements of the assembly are symmetrically positioned with respect to the axis of rotation of the hub, the hub always will be dynamically balanced. It will be noted that the head of the bolt 21 is easily accessible so that the hub may be quickly removed from the shaft of the driving means if desired.

There is shown in Fig. 5, a modied form of Ythe present invention, particularly the means by .which the' huband blades are mounted to the shaft of the driving means. In this form of the invention, -the hub is identical with the hub show-n inthe previously referred to figures and the blades are likewise identical and mounted and .secured toi the hub inthe samemanner-as are the blades lof .thatform .of the 'invention shown in Figs.11 tol inclusive.

The reinforcing diskfin this form ;ofA the .invention, does not have an integrali-sleeve, but, 1as shown, a separatesleeve 33..isL centrally'carried by the` disk 34. The .sleeve33 is provided with an annular flange 35 at the one end thereof-which engages the one face ofthe disk 34andpreven-ts the sleeve frcmbeing pulled through the aperture in the disk 34 through which the rsleeve projects. The opposite end ofthersleevelis.peened'over to form a retaining head-36 lyingwithinarecess 31 formed at the nose of the. hub. The1sleevef33 is formed witha camming surface;38' cooperating with camming surfaces '39 formed on fa" sleeve 4III) identical with sleevel22 inithel'rstif'described form of the invention.

The threaded bolt .4I vreceived 'Within the threaded socket 42 ofthe sleevef40fdrawsthe latteroutwardly of the shaft i432 until the. actionrof the .camming surf aces 1 38 and .39 `clamp, the/split 'end thereof inl'toclamping engagement .with theend of the shaft 43. It 'will be seen-again that al1 elements are symmetricallylpositione'd with respect tothe 'axis .'of Vrotation of the fhub and thehub will again always .be dynamically balanced.

In this vform of the invention, the .disk 34?. reinforcing the-rear edge'of the hub willbe held against the rear 'edge partial'lyby the `sleeve.33,

the opposite ends'of which'are secured tolthe Amovement in either'direction'transverse'to the axis thereof, said means Uclosing"saidentrance portions and holding the bladesinthe slots.

2. In .a fan, a hollow'substantially -conical shaped 'hub having slots'forme'd thereinanfd' opening at the rear thereof; bladeszmounted in said slots; and means "disposed iaboutthe 'rear edge'of said hub'for reinforcing the reare'dge of the hub and for holdingtheblades in the slots, saidrneans including fa 'diskprovided with a'circula'r groove of the' sameY diameter -fas the rear edge of said hub, the walls of said groove holding the rear edge of said hub against movement in either direction transverse to the longitudinal axis thereof.

3. In a fan, a hollow hub having slots formed therein and opening at the real` thereof; blades mounted in said slots; and means disposed about the rear edge of said hub for reinforcing the rear edge of the hub and for holding the blades in the slots, said means including a disk provided with a circular groove of the same diameter as the rear edge of said hub and having an annular ange engaging the outer surfaces of said hub contiguous to the rear edge thereof, said flange engaging the trailing edges of the blades and holding the latter against sliding movement in the slots.

4. In a fan, a hollow hub having slots formed therein and opening at the rear thereof; blades mounted in said slots, said slots being widened at the rear edge of said hub to facilitate the insertion of the blades therein, said blades being inserted in said slots by sliding movement; and means disposed about the rear edge of said hub for reinforcing the rear edge of said hub and holding the blades in the slots, said means including a disk provided with a circular groove of the same diameter as the rear edge of said hub and having an annular flange engaging the outer surface of said hub contiguous to the rear edge thereof and covering the widened portion of said slots, the forward edge of said flange engaging the trailing edges of the blades and holding the same against sliding movement in the slots.

5. In a fan, a hollow hub having slots formed therein and opening at the rear thereof; blades mounted in said slots; means disposed at the rear of said hub for reinforcing the rear edge of the hub and for holding the blades in the slots; a drive shaft having the end thereof disposed within said hub; and common clamp means actuated by a single operation for securing the hub to said shaft and the reinforcing means to the rear edge of said hub.

6. In a fan, a hollow hub presenting at the rear thereof a substantially circular edge, said hub formed with a plurality of slots opening at said edge; a plurality of blades mounted in said slots; means for reinforcing said edge and closing said slots; a shaft; means within said hub for clamping said reinforcing means against the rear edge of said hub and for securing the hub to said shaft; and means carried exteriorly of said hub for causing said last-named means to simultaneously clamp the reinforcing means against said edge and secure the hub to said shaft.

'7. In a fan, a hollow hub having slots formed therein and opening at the rear thereof; blades mounted in said slots; means for reinforcing the rear edge of said hub and for holding said blades in said slots; a shaft having an end thereof disposed within said hub; means for clamping the hub to the shaft comprising camming surfaces and cooperating clamping elements extending axially of the hub and positioned to engage the shaft for a substantial area thereof; and means extending axially of the hub for moving the clamping elements relative to the camming means and laterally with respect to the shaft into clamping relation with the shaft to lock the hub thereto and the reinforcing means to the rear edge of said hub.

8. In an electric fan, a hollow hub having a plurality of slots formed therein and opening at the rear thereof; blades mounted in said slots;

a disk disposed at the rear of said hub and having an annular groove receiving the rear edge of said hub; a sleeve carried by saidY disk and extending axially of the hub; camming surfaces formed in the bore of said sleeve; and a clamping sleeve slidable in said bore and having one end slit so as to form clamping elements adapted to cooperate with the camming surface in the bore and the other end threaded to engage a bolt mounted in the hub to extend axially of the same, whereby when the bolt is turned the clamping sleeve will slide and move the clamping elements laterally into gripping relation with the shaft, movement of the clamping sleeve causing the disk to be securely clamped against the rear edge of the hub.

9. In a fan, a hollow hub having a plurality of slots formed therein and opening at the rear thereof; blades mounted in said slots; a disk having an annular groove receiving the rear edge of said hub; an annular flange carried by said disk engaging the outer surface of said hub contiguous to said rear edge and engaging the trailing edges of said blades to prevent sliding movements of the blades in the slots; a sleeve carried by said disk extending inwardly thereof along the axis of the hub; a drive shaft having the end thereof disposed within the sleeve; and means within the sleeve and coaxial with the shaft for gripping the sides of the shaft with a radial pressure and for clamping the bottom wall of said groove against the rear edge of the hub.

10. In a fan, a hollow hub having a plurality of slots formed therein and opening at the rear edge thereof; a plurality of blades mounted in lsaid slots; a disk disposed at the rear of said hub having an annular groove receiving the rear edge of said hub and holding said edge against movement in either direction rtransverse to the longitudinal axis thereof; a sleeve carried by said disk and extending inwardly thereof along the axis of the hub; a shaft having the end thereof disposed within the sleeve; means within the sleeve and coaxial with the shaft for gripping the end of the shaft and for clamping the bottom wall of said groove against the rear edge of the hub; and means for operating said first-named means to hold the hub on said shaft and against relative rotation with respect thereto when the fan is under load.

11. In a fan, a hollow substantially conical shaped hub having a plurality of slots formed therein and opening at the rear thereof; blades of resilient flexible material mounted in said slots to project from the outer surface of the hub; means on the edge of the blade within the hub engaging the interior surface of the hub for holding the blade against movement radially of the hub; and means closing the open end of said hub and including means disposed on opposite sides of the rear edge of the hub for reinforcing the same, said means closing said slots and holding the blades against sliding movement in the slots.

12. In a fan, a hollow substantially conical shaped hub provided with a plurality of slots having entrance portions at the rear thereof; blades of resilient flexible material mounted in said slots to project from the outer surface of the hub; a pluraliy of projections extending transversely of the blade along the edge of the blade and adapted to engage the interior surface of the hub to hold the blades against movement radially of the hub; a disk formed with an annular groove receiving the rear edge of the hub to reinforce the same; and an annular flange carried by said `disk engaging the outer surface of the hub adjacent the rear edge thereof and closing the entrance portions of Ysaid slots, said flange engaging the trailing edges of the blades for preventing sliding movement of the blades in the slots.

13. In a fan, a hollow hub having a plurality of slots formed therein Vand opening at the rear edge thereof; a pluraliy of blades mounted in said slots; a disk having an annular groove receiving the rear edge of said hub and closing thel open end of said slots; a sleeve having one end secured to the nose of saidh-ub and the `other end secured to said disk and securely holding the disk against the rear edge of said hub; a camming surface provided in the bore of said sleeve; clamping elements mounted to slide in the sleeve and havingA parts adapted to engage the camming surface; and means for sliding the clamping elements to move them relative tothe carnming surface of the sleeve to cause them to move laterally to clamp the drive shaft and hold the hub thereon against relative movement.

GUSTAVE F. BA1-IR. 

